Combustion engine



Patented Sept. i8, i923.

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uni ses Parenti y@sentia a d 'WILLIAM BROWN, OF ANNANDALE, SOUTH WLES, AUSTRALIA.

COMBUSTION ENGINE.

Application led September 17, 1920. d Serial No. 410,885,

tion.

Y d Thisfinvention relates to Afour-stroke cycle combustion engines in which motive power is obtainedv from a mixture of combustible gases or'vapors drawn from a carburetter f or other source ofA supply whichv is com- '2 pressed, ignited, `and expanded inthe cylinder or cylinders thereof.

V.The invention has relevance to a new method of loperating such engines.l and to means for enabling said method to be car-` ried out. By my said method of operation otsuch engi-nes a greater quantity of the available heat of the combustiblev charge burnt in the cylinder' or cylinders is converted into power than is the case when such ent known.4 The method as is now generally employed vconsists in compressing a combustible mixture of'gases or vapors and exploding same in the cylinder or cylinders of the" engine. The pressure which is exerted on the piston bylthe explosion causes it to move on the power stroke and thecrank is carried through ahalf revolution. About the time the piston has completed its power stroke and the pistorl ismoving on the exhaust stroke the exhaust valve opens and which both the inlet and'exhaust valves ot;

the engine are closed. The whole of the charge admitted to the engine cylinder .1s

` Whole of thereof but only for approximately the first .chamber engines are operated'by the method at pres-l thencompressed and its temperature increased to the point required for'ignition, and it is ignited when the piston has neared the end of its compression stroke. Only one explosion occurs in the cylinder or cylinders of the engine for every two revolutions of the crank and during each cycle only one powe stroke is obtained.

In my method of operating such engines the inlet valve is not opened during the the suction stroke of the half of such stroke. of such stroke of the .charge for the cylinder is `drawn from a During the other half storage reservoir which is in communication with the cylinder during the latter half of the suction stroke of the piston. The valve controlling the port leading from the storage to the cylinder remains open up' to the point at or about which the piston will have moved through the i'rst half of its compression stroke. Whilst the storage reservoir is open to the cylinder during part of the compression stroke of the piston part of the charge admitted to the engine cylinder is returned to the storage reservoirto be again transferred to the cylinder afterthe inlet valve of the engine has been closed on its succeeding suction stroke. The remainder of the charge left in the cylinder is compressed, ignited, and the gases resulting from the explosion are permitted to expand and are expelled from the cylinder during the exhaust stroke of the piston.

am aware that. four-stroke cycle combustion engines are already known in which a portion of the charge admitted to the cylinder from a storage reservoir during the suction stroke of the vpiston is expelled to said reservoir 'during a portion of the compression. strokev of the piston and the remainder is compressed and exploded in the ordinary manner. In such engines, however, the inlet valve remains open for the whole of the suction stroke ofthe piston and during a portion of its compresslon stroke" and part of the charge admitted to the cylinder is returned to the reservoir from which it was originally drawn through the inlet piston piston the combustible A l s'o ends of the tappet rods 23, 24 and 25 convalve. By my method of operatingfourstroke cycle rcombustion engines the inlet .valve is not open during the whole of the suction stroke and for part of the compression stroke of the piston; it is only open `for approximatelyfthe irst half of the suc-A tion stroke of the piston.

The accompanying drawing shows one l embodiment of means for carrying out the bustible charge storage chamber 9.

- al screw-down plug or the like which may invention applied to an internal combustion engine in which the cylinder lhas a water jacket 2. The piston 3 is connected to the crank pin 32 by the connecting rod 33 and is f capable of reciprocation within the cylinder f1 which is open at its bottom to the crank case 4. At its head the cylinder is provided with a cover 5 having seatings for the inlet valve 6, the exhaust valve 7 and the valve 8 which controls the port opening between the interior Aof the cylinder and the ppm# assageslO and 11 in the cover '5 are in communicatio'n respectively with the induction pipe 12 from a carburetter or other source of fuel supply and the storage chamber 9. A

by-pass 13 lfitted with a non-return valve 14 connects the induction pipe 12 and passage O with the top of the storage chamber 9. The head of this chamber may also be furnished-with a safety valve 15 and also with be brought into contact with the\spindle of the non-return valve 14 to prevent such valve oppning as it would otherwise` tend to do w en the valve 8 were opened. If, however,

itshould be desired to admit a combustible v cams`197 20 an meshin mounted three cams'19, 20 and 21 which are adapted respectively to contact at predetermined times with the rollers 22 on the lower nected respectively with the tappet levers 26, 27 and 28 which are adapted to contact respectively with the spindles 29, 30 and 31 of the vvalves 6, 7 and 8 to open said valves when the tappet. rods 23, 24 and 25 are moved upwardl by the operation of the The cam 19 is shaped and set to. operate the inlet 'valve 6 in proper timing with the 'movements of the piston 3, but to -allow said valve to close at approximately the time when the piston will have reached lthe completion of the first half of its suction'stroke.

herein-and that t -samelmay be varied to suit practical worklng conditions of vfour-stroke cycle combus v pon the latter shaft. are

Similarly the cam 2O is shaped and set to operate the exhaust valve -7 to enable the products of lcombustion of the charge in the .cylinder to befdischarged therefrom on the exhaust-stroke ofthe piston 3. As the valve 8 is only to be opened approximatelyl at'the time the inlet 4valve 6 isclosed on the suction stroke of the piston 3 and to be closed at or about the point at which the piston will have completed the first half of its compression stroke the cam 21 which oper-l ates this valve i's so shaped and set to operate the` valve 8 in this manner.

`lf the movements of the inlet and storage chamber valves are to b e controlled bylgov-l ernor mechanism operating on the hit-ormlss pr1nc1ple, such mechanism may be constructed and set to open such valves at proper timing when the engine is at normalspeed, and to control the movements of the valves for admitting or cutting off supplies of combustible charges to the engine cylin der depending on the speed of the engine.

It will be evident that the invention may i be carried out by means other than those shown in the drawings and described herein, and I wish it to be understood that the principal character of the invention resides in the method ofopleration which vis disclosed e means for el'ectuating tion `engines of different types.

As` only a portion of the combustible charge admitted to the cylinder is coinpressed and exploded7 the products of the exploded charge are permitted greater ex-fv -pansion than t e expansion allowed in fourstroke cycle combustion engines as` ordinarily.operated at present. The thermal einciency of such engines is therefore increased when the are operated with my method. Further t e expanded gases are allowed to cool to a greater. extent by the utilization of my method, and they are thus expelled from the cylinder of the engi'ne in a cooler condition than they are expelled from eingines at present in use.

What I claim as my invention and desire to secure by Lettersv Patent-isz l. In aj combustion.- engine, a cylinder having ports therein, a piston reciprocally mounted 1n said cylinder, a main inlet valve controlling one of said-ports, agaseous fuel V reservoir communicating with another -of said ports,`a valve in the last mentioned port controllin passageof gaseous fuel between the cylin er and .the reservoir, actuating means for the inlet valve, actuating means for the second mentionedv'al've'operatingto open the latter substantially coincident with the closure of the main inlet valve to establish communication between the cylinder and reservoir andto maintain said commumomo@ nication throughont a, portion of the compression stroke of thc piston, a, fuel induction pipe associated with the rst mentioned port, a. non-return valve adapted to permit admission of combustible gas to said roservoir from the induction Vpipo during the iat-w ter part. of the suction stroke of the piston and while the reservoir is in communication with the engine cylinder.

,return valve to prohibit admission of said combustible gas to said reservoir.

In testimony whereof l ax my signature. 15

WLLAM BROWN. 

